1. Field of the Invention
The present invention relates to a portable terminal which has an antenna disposed within a housing for accommodating a circuit board, and more particularly to an embodiment of mounting the antenna.
2. Description of the Related Art
In order to improve the beauty and the like of an exterior design of, for example, a portable terminal such as a cellular phone, there are proposed those which have an antenna for communications disposed within a casing without exposing to the outside of the casing.
A portable terminal E shown in FIG. 7, FIG. 8A and FIG. 8B has a circuit board B, which has unshown various types of electronic parts mounted on it, within a casing (housing) C comprised of a lower case L and an upper case U which are mutually assembled and also has a communications antenna A disposed within the casing C.
The antenna A has a flat-plate antenna body Aa formed of a sheet metal such as stainless steel and a connection tongue piece Ab protruded from the antenna body Aa and is mounted in a prescribed position within the casing C by fitting the antenna body Aa into slits of ribs La, La formed in the lower case L.
Meanwhile, a connection spring S is attached to a connection pattern Bp, which is formed on the surface of the circuit board B, by means such as soldering or the like, and the connection tongue piece Ab of the antenna A assembled within the casing C as described above is contacted to the connection spring S so as to connect a communication circuit (not shown) configured on the circuit board B to the antenna A.
The above-described conventional portable terminal E has a structure in which the antenna A (antenna body Aa) is disposed between an end wall Le of the lower case L and an edge Be of the circuit board B. But, in the portable terminal E configured as described above, it is difficult to have a large clearance w between the edge Be of the circuit board B and the antenna A (antenna body Aa) because the space is limited, and there is a disadvantage that the antenna performance is degraded considerably when transmitting and receiving because the antenna A (antenna body Aa) is close to the circuit board B and various types of metallic substances disposed around the circuit board B.
With respect to the above disadvantage, the degradation in antenna performance when transmitting and receiving can be prevented by increasing the clearance w between the edge Be of the circuit board B and the antenna A (antenna body Aa) but there was a problem that the portable terminal E had an unexpectedly large appearance because the casing (housing) C became large as the clearance w was increased.
Under the circumstances as described above, the present invention provides a portable terminal which secures the clearance between the parts such as a circuit board in the housing and the antenna without involving an unexpected enlargement of the housing and can prevent the antenna performance from lowering when transmitting and receiving.
In the above-described conventional portable terminal E, the entire antenna A assembled to the ribs La, La in the lower case L is exposed within the casing C, and the edge portion of the flat-plate antenna body Aa, namely a ridgeline portion where a flat portion and a peripheral surface portion in the plate thickness direction meet each other, is also exposed, so that static electricity, which enters from the outside via a gap between the lower case L and the upper case U, tends to hit the edge portion, and if static electricity hits the antenna A, there was a possibility that the communication circuit connected to the antenna A was destroyed.
Under the circumstances described above, the present invention provides a portable terminal which can prevent the communication circuit from being destroyed even if static electricity from the outside hits the antenna.
And, the above-described conventional portable terminal E connects the communication circuit (not shown) configured on the circuit board B and the antenna A by contacting the connection spring S attached to the connection pattern Bp formed in the circuit board B to the connection tongue piece Ab disposed on the antenna A. Thus, the number of parts used for the connection of the antenna A and the communication circuit (not shown) was many, involving a disadvantage that the production process became complex.
Under the circumstances described above, the present invention provides a portable terminal which can achieve the reduction of the number of parts used for connection of the communication circuit on the circuit board and the antenna.